This is the 10755th most frequent Korean word.
귀국할
"To return to one's home country."
Here, '귀국할' is used as the future tense form of the verb '귀국하다' (to return to one’s home country), suggesting a deliberate plan in the future.
그는 다음 주에 귀국할 예정이다.
He is scheduled to return to his country next week.
In this sentence, '귀국할' introduces the subordinate clause indicating the specific action occurring while returning to one’s home country.
귀국할 때 친구들에게 선물을 사왔습니다.
When I returned to my country, I brought gifts for my friends.
Here, '귀국할' modifies the noun '일' (day, matter), describing the action contextually tied to the imagined event.